What will happen if the oil needle of motorcycle carburetor doesn't work well

First, carefully check whether there is air leakage at the connection position between carburetor and cylinder head. This position should be solved, and then there will be adjustment problems. Generally, after tightening, the rotating speed will decrease, gradually retreat and start to increase, and fine-tune it around 1.5-2. If the carburetor plunger is loose, the air needle may fail. If the gas needle is tightened repeatedly, there will be a problem (rare) between the top end of the gas needle and the inner cone opening, so it can only be replaced.